It is indeed a macro in vim. The key to realizing what's going on is to realize that when I made it I didn't sit down an type that out... well, not really.

Rather I just pressed qf (which starts recording a macro to 'f'), then preformed the sequence of commands that would need to be done to do what I wanted. You do it step by step while watching what's actually going on, so it's not as hard as it seems. Then from then on I can just press @f to do what would normally take all of those keys.

broken down, this is how the macro works:

zE - clear other folds

k - up

zf - start creating a fold from here to...

gg - ...the top of the document

j - down

% - go to the matching bracket

j - down

zf - start creating a fold from here to...

G - ...the bottom of the document

I don't really remember why those ups and downs were needed, maybe they're not. Just how I typed it out at the time.